The invention relates generally to valves operable to dispense fluids, and particularly to fluid dispensing valves (e.g., xe2x80x9cbite valvesxe2x80x9d) having an orifice opened by an applied transverse displacement to a valve body, such as may occur by biting them in a human mouth.
Fluid dispensing valves are known, including certain valves commonly used in commercially available personal hydration systems. Such personal hydration systems typically incorporate a bite valve disposed at the end of an elongated conduit attached to a fluid source. The fluid source may therefore be stored in a backpack, or other remote carrying device, with the bite valve being in a convenient proximity to a mouth for dispensing a quantity of fluid, as desired.
A xe2x80x9cbite valvexe2x80x9d is named for the technique commonly used to permit fluids to flow through the valve. A person simply bites the valve body transversely to squeeze the body sides together. As the body is squeezed between a user""s teeth, a fluid flow path is opened, and fluid may flow through the valve.
A first type of bite valve is used in a range of products sold by the CamelBak(trademark) Company. A second type of bite valve is used in a variety of personal hydration products sold under the Platypus name by Cascade Designs(trademark). The CamelBak(trademark), valve and Platypus valve are similar in that each has a vertical slit disposed at the distal end of a soft valve body. Biting the body causes the slit to open, permitting a flow of fluid through the bite-formed opening in the slit.
A third type of bite valve is disclosed in U.S. Pat. No. 5,971,357, issued to Denton et al. on Oct. 26, 1999, and assigned to Wolfe Tory Medical, Inc. The disclosure of U.S. Pat. No. 5,971,357 is hereby incorporated as part of this disclosure as though set forth herein in its entirety. The Wolfe Tory valve has a stiff inner core member disposed inside a soft conduit sealing member. Biting the soft conduit opens a fluid flow path through the core member.
All three types of bite valves described above suffer from a requirement to orient the valve in a user""s mouth for proper operation. In fact, the Platypus and CamelBak(trademark), valves both have oblong cross-sections to assist in such orientation. Biting any of the prior-mentioned valves in a mis-oriented position can result in a failure to cause the opening mechanism to deform sufficiently to permit a flow of fluid through the valve orifice.
The three prior-mentioned valves also may suffer from the tendency to leak under certain conditions. A first leak promoting situation is when contents of the fluid reservoir are excessively pressurized. Each of the above described bite valves has a self-biased valve seal. Sometimes a fluid reservoir stored in a backpack is inadvertently pressurized by a person sitting on the backpack, or placing other objects on top of the backpack. Pressurized fluid acts on the self-biased valve seals in a direction to open the valves, and to permit fluid to escape. A second leak promoting situation is when the self-biased valve material loses resilience, causing the seal to be less effective. Resilience may be lost due to material hardening over time, or due to fatigue from use.
Furthermore, all three valves suffer from a relatively low throughput, or deliverable flow rate. It would be an advance to develop a bite valve capable of increased fluid throughput, and to overcome the other limitations described above.
The invention may be embodied as a valve operable to restrict fluid flow through a conduit. Such a valve includes a valve seal member having an inside perimeter surface oriented to circumscribe an opening of the valve, and through which opening a fluid path exiting the valve exists. A valve seal is formed at the valve opening between a flexible conduit having an exterior surface on a first end, and the seal member. The flexible conduit surface is adapted to form a self-biased engagement with the perimeter surface of the seal member to occlude and resist fluid flow through the opening. The valve may be opened to permit fluid flow by effecting a transverse displacement of a localized portion of the exterior surface of the flexible conduit relative to a corresponding engaged portion of the inside perimeter surface of the seal member.
Exemplary embodiments of the valve are sized to fit within a human mouth. A user""s teeth can bite on the flexible conduit to effect the transverse displacement required to open the valve. Certain embodiments of the valve can be adapted to effect a transverse displacement of the flexible conduit independent of valve rotation, about a delivered fluid axis, in a mouth.
A valve may include a positive stop mechanism operable to resist fluid discharge through the valve opening. Examples of such positive stop mechanisms include xe2x80x9cbayonetxe2x80x9d locking mechanisms and sliding mechanisms in combination with structure to augment the valve seal. Certain sliding mechanisms can be adapted to bring an end of the flexible conduit into contact or plug fit engagement with an end seal.
Valves constructed according to the present invention are characterized by having a pressure augmented seal. That is, fluid pressure upstream of the valve opening actually increases the contact pressure between sealing surfaces, further resisting fluid flow through the valve.
Another way to describe the invention is as an improved bite valve to regulate fluid delivery to a human mouth. The valve provides an inside seal member having a first flexible portion configured in self-biased harmony with an outside seal member such that a localized transverse displacement, directed inwardly, of the first flexible portion opens a fluid flow path through an opening formed, as a result of separation of contact between the inside and outside seal members, by biting the valve. When a user bites the flexible portion, a fluid flow path is formed by a corresponding transversely inward deflection of the first flexible portion with respect to the outside seal member.
Sometimes the valve may be constructed with the outside seal member having a flexible portion to improve the feel of the device inside a user""s mouth. In any event, the valve is typically attached, at a proximal end, to a fluid delivery conduit. An opposite end of the fluid delivery conduit typically extends to a remote fluid reservoir, although such is not a requirement. A fluid reservoir can be attached directly to a valve constructed according to the invention.
The invention may also be described as a valve having an inside seal member formed by a transversely flexible first conduit functioning to guide fluid from a first end toward a second end, and having a first seal surface located at an exterior perimeter of the second end. The conduit is arranged in harmony with an outside seal member to form a valve. The outside seal member is generally configured and arranged as a cap to block distally directed fluid flow exiting the second end of the first conduit. Preferred outside seal members will have a proximally directed flange forming a second conduit. The second conduit forms an inside surface carrying a second seal surface. The first seal surface on the first conduit is self-biased for engagement with the second seal surface to form a fluid seal to resist fluid flow through the valve. The valve is opened to permit fluid flow by effecting a radially inward displacement, of a localized portion of the first seal surface relative to a corresponding portion of the second seal surface.
The valve includes a support member adapted to locate the outside seal member in a functional position relative to the inside seal member. A suitable support member can be a post element disposed interior to the first conduit. Alternatively, a support member can include one or more post elements disposed exterior to the first conduit. A support member can also be a component of a positive stop mechanism to resist undesired fluid flow through the valve.
A post element can include an anchor disposed proximally from the outside seal member and adapted to maintain the valve in registration with a fluid supply conduit. One type of anchor includes a barb element. Another type of anchor can include a fitting adapted to index with a fluid supply tube. Certain of such fittings can change an angle of fluid flow from the fluid supply conduit.
These features, advantages, and alternative aspects of the present invention will be apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.